Wireless in building telephones deploying a pico-cellular architecture allow employees to work away from their desks without the worry associated with missing incoming callers. A communication system such as this consisting of a central controller, base stations connected to the controller, and wireless handsets carried by the employees have allowed increased freedom and accessibility in the work place.
The central controller manages all incoming calls for the individual wireless handsets using an in building telecommunication network. The network is divided into cells which service the handsets in a defined area. Each cell contains a base station which exchanges voice and data information with the handsets located within the cell's coverage area. When a call arrives for a particular handset, the controller determines the cell location of the requested handset and alerts the user with a notification alarm on the handset.
As aforementioned, one key advantage of this system is the ability of the user to work away from their work area while not missing incoming calls. A problem results from the fact that this inevitably increases the time the employee is away from his/her Personal Computer (PC) and its associated applications and databases. This reduction in access to valuable resources can harm productivity and limits the true freedom gained by the use of the portable telephone system.
The ability to communicate caller identification data from the central controller to the handset is well known. Generally, this information which includes the name and/or number of the calling party is transferred to the liquid crystal display (LCD) of the handset when the handset is alerted of an incoming call. Such an apparatus is typified in U.S. Pat. No. 5,581,599 Tsuji et al, issued Dec. 3, 1996, the disclosure of which is incorporated herein by reference. This innovation allows limited information about the calling party to become available to the user of the portable telephone. This information, although useful, does not allow a user to gain access to applications or databases that may be located on a PC. If a user required additional information about a calling party before accepting the call, it would necessitate access to a PC and the specific databases needed.
There are presently available digital telecommunication systems that allow data sessions between the portable handset and the central controller. These data sessions may be initiated by the user or by applications running on a personal computer (PC) connected to the controller. Samples of these systems include the Companion 200 and Meridian Companion Mobility Option (MCMO) produced by Northern Telecom Limited and the Pocket Communication Systems (PCS) PCS50E, PCS150E, and PCS2000E produced by SpectraLink Corporation. These data sessions allow the user to access applications located on a server connected to the central controller remotely through a handset. While the user is away from a PC, this system allows for the activating and running of computer programs that may be required without prescribing that the user be situated at the same location as the PC. This increases the accessibility of information to the user while away from a PC.
An inherent problem that occurs through the use of the portable telephone as both a means for voice communication and a means for data communication is the inability of the central controller to access the user for a voice call while the user is engaged in a data session on the handset with the server. This reduces the availability of the user to outside callers and limits the advantages gained by the portable telephone system.